Methods of harvesting and implanting follicular units using a coaxial tool

ABSTRACT

A method of transplanting a hair follicular units includes aligning a longitudinal axis of a harvesting cannula of a tool assembly with a longitudinal axis of a selected follicular unit, advancing the harvesting cannula relative to the body surface so that a tissue coring distal end of the harvesting cannula penetrates the body surface surrounding the selected follicular unit to a depth sufficient to substantially encapsulate the follicular unit, withdrawing the harvesting cannula distal end from the body surface with the follicular unit retained in an interior lumen of the harvesting cannula, advancing an implanting cannula of the tool assembly over the harvesting cannula relative to the body surface so that a tissue piercing distal end of the implanting cannula punctures the body surface and forms an implantation cavity therein, and displacing the follicular unit from the harvesting cannula lumen into the implantation cavity.

RELATED APPLICATION DATA

The present application claims the benefit under 35 U.S.C. § 119 to U.S. provisional patent application Ser. No. 60/722,521, filed Sep. 30, 2005, 60/753,602, filed Dec. 22, 2005, and 60/764,173, filed Jan. 31, 2006, which are all hereby incorporated by reference.

FIELD OF INVENTION

This invention relates generally to apparatus used for harvesting and implantation of hair follicular units.

BACKGROUND

Hair transplantation procedures are well-known, and typically involve (in a patient having male pattern baldness) harvesting donor hair grafts from the side and back fringe areas (donor areas) of the patient's scalp, and implanting them in a bald area (recipient area). Historically, the harvested grafts were relatively large (3-5 mm), although more recently, the donor grafts may be single follicular units. In particular, “follicular units” are naturally occurring aggregates of 1-3 (and much less commonly, 4-5) closely spaced hair follicles that are distributed randomly over the surface of the scalp. In one well-known process, a linear portion of the scalp is removed from a donor area by dissection with a scalpel down into the fatty subcutaneous tissue. The strip is dissected (under a microscope) into the component follicular units, which are then implanted into a recipient area in respective puncture holes made by a needle. Forceps are typically used to grasp and place the follicular unit grafts into the needle puncture locations, although other instruments and methods are known for doing so.

In “Androgenetic Alopecia” (Springer 1996), M. Inaba & Y. Inaba disclose and describe a method for harvesting singular follicular units by positioning a hollow punch needle having a cutting edge and interior lumen with a diameter of 1 mm, which is about equal to the diameter of critical anatomical parts of a follicular unit. The needle punch is axially aligned with an axis of a follicular unit to be extracted and then advanced into the scalp to cut the scalp about the circumference of the selected follicular unit. Thereafter, the follicular units are easily removed, e.g., using forceps, for subsequent implantation into a recipient site with a specially devised insertion needle.

Published U.S. Patent Application 20050203545 (Cole) discloses an instrument for the extraction of individual follicular units that purportedly allows for a more precise penetration depth and angle with respect to the skin surface of the skin of a patient.

Published U.S. Patent Application 20050267506 (Harris) discloses a method and apparatus for the extraction of follicular units by first scoring the outer skin layers with a sharp punch, and then inserting a separate blunt punch into the incision to separate the hair follicular unit from the surrounding tissue and fatty layer.

U.S. Pat. No. 6,585,746 (Gildenberg) discloses a hair transplantation system utilizing a robotic system, including a robotic arm and a hair follicle introducer associated with the robotic arm. A video system is used to produce a three-dimensional virtual image of the patient's scalp, which is used to plan the scalp locations that are to receive hair grafts implanted by the follicle introducer under the control of the robotic arm. The entire disclosure of U.S. Pat. No. 6,585,746 is incorporated herein by reference.

SUMMARY

In accordance with one aspect of the invention, a method of transplanting a hair follicular unit using a multi-part tool assembly includes (i) aligning a longitudinal axis of an inner (“harvesting”) cannula with a longitudinal axis of a selected follicular unit to be harvested from a donor area of a body surface; (ii) advancing the harvesting cannula relative to the body surface so that an open, tissue coring distal end of the harvesting cannula penetrates the body surface surrounding the selected follicular unit to a depth sufficient to substantially encapsulate the follicular unit; (iii) withdrawing the harvesting cannula from the body surface with the follicular unit engaged by and retained in an interior lumen thereof; (iv) advancing an outer (“implanting”) cannula over the coaxially disposed harvesting cannula so that a tissue piercing distal end of the implanting cannula punctures a recipient area of the body surface and forms an implantation cavity therein; and (v) displacing the follicular unit from the harvesting cannula lumen into the implantation cavity.

The tool assembly may be hand-held and positioned. In the alternative, the tool assembly may be attached to, and positioned by, a moveable arm of an automated system, e.g., a robotic arm system. Movement of one or both of the harvesting and implanting cannulas relative to each other and/or to the remainder of the tool assembly (whether hand-held or carried by an automated positioning system) may be provided by a number of different mechanical, electromechanical, pneumatic, hydraulic, magnetic, and other known systems and mechanisms for effecting controlled movement of the respective cannulas. While the implanting and harvesting cannulas are preferably axially aligned, other embodiments are possible.

For harvesting, a longitudinal axis of the harvesting cannula is axially aligned with a longitudinal axis of a selected follicular unit to be harvested. Depending on the embodiment, positioning of the harvesting cannula relative to the selected follicular unit may be manual or fully automated. In one embodiment, an image-guided robotic system including a robotic arm is used to position and align the respective harvesting cannula and follicular unit. The harvesting cannula is advanced over the follicular unit, with its distal coring end penetrating the body surface into the subcutaneous fatty layer surrounding and underlying the follicular unit. The harvesting cannula is then withdrawn from the body surface to thereby extract the follicular unit, which is carried in the harvesting cannula lumen.

Movement of the harvesting cannula relative to the body surface may be manual, semi-automated, or completely automated. The harvesting cannula may be fixed or independently moveable relative to the remainder of the tool assembly, whether the tool assembly is hand-held or attached to a moveable arm. In embodiments in which the tool assembly is carried on an automated (e.g., robotic) arm, movement of the harvesting cannula relative to the body surface may be performed by movement of the arm relative to the body surface, movement of the harvesting cannula relative to the automated arm, or a combination of each. Similarly, in hand-held embodiments, movement of the harvesting cannula relative to the body surface may be performed by movement of the operator's arm relative to the body surface, movement of the harvesting cannula relative to the tool assembly, or a combination of each. In some embodiments, the harvesting cannula is rotated about its longitudinal axis as it penetrates the body surface to enhance its tissue-coring effectiveness.

In some embodiments, the wall of the harvesting cannula lumen may be textured in order to facilitate grasping and extracting the follicular unit. In some embodiments, a vacuum source may be selectively placed in communication with the harvesting cannula lumen to apply a proximally directed “pulling” force to facilitate grasping and extracting the follicular units. These features may also be helpful in retaining the follicular unit in the harvesting cannula lumen after it is harvested.

For implantation, the tool assembly is repositioned (whether manually or by using an automated system) to a selected implantation site in a recipient area on the body surface. A longitudinal axis of the implanting cannula may be aligned with a desired orientation of the follicular unit, when implanted. Again, this alignment may be performed manually or by an automated system, e.g., by using an image-guided robotic system in one embodiment. The tissue-piercing distal end of the implanting cannula is advanced into the body surface, creating a subcutaneous implantation cavity of an appropriate depth and size for receiving a follicular unit being implanted. This “puncture motion” by the implanting cannula is preferably very rapid in order to minimize trauma to the tissue surface in the implantation cavity, e.g., akin to the motion of a spring-loaded finger pricking device used for obtaining small amounts of blood for testing.

In one embodiment, a follicular unit is moved axially from the harvesting cannula lumen (where it has remained undisturbed since it was harvested) into the distal end portion of the implanting cannula lumen by an obturator (plunger) disposed in the harvesting cannula lumen. This repositioning of the follicular unit may take place before, during, or after the implanting cannula punctures the body surface. The obturator thereafter maintains the relative position of the follicular unit in the implantation cavity as the implanting cannula is withdrawn from the body surface by translational movement relative to the obturator. In others embodiment, the follicular unit is deposited directly from the harvesting cannula lumen into the implantation cavity, e.g., by the obturator, or by applying a distally directed “pushing” force using a source of pressured air placed in communication with the harvesting cannula lumen.

Other and further embodiments, objects and advantages of the invention will become apparent from the following detailed description when read in view of the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which:

FIG. 1 is a perspective view of a robotic arm system used for positioning and orienting a pair of coaxially-disposed cannulas extending from a distal opening of a tool assembly housing carried by the robotic arm and used for harvesting and implanting human hair follicular units.

FIG. 2 is a close-up of the distal portion of the tool assembly housing shown in FIG. 1.

FIG. 3 is a perspective view of a multi-part tool for use in the tool assembly in the system of FIG. 1.

FIG. 4 is lengthwise sectional view of the multi-part tool of FIG. 3.

FIG. 5 is a perspective view of a motor drive assembly for operatively coupling with the multi-part-part tool of FIG. 3 in the tool assembly of the system of FIG. 1.

FIGS. 6A and 6B are simplified, partially cut-away views of alternative implantation procedures carried out using the three-part tool of FIG. 3.

FIG. 7 is a partial-schematic, partial perspective view of one embodiment of the tool assembly of the robotic system in FIG. 1.

FIG. 8 is a partially cut-away sectional view of a holding unit located within a motor drive assembly in the tool assembly of FIG. 7.

FIG. 9A is a lengthwise sectional view of a multi-part tool for use in the tool assembly in the system of FIG. 7.

FIGS. 9B-9D illustrate variations of a distal end of a follicular unit harvesting cannula needle of the tool assembly of FIG. 9A.

FIG. 10 illustrates the multi-part tool of FIG. 9A operatively engaged with the holding unit of FIG. 8.

FIGS. 11A-D illustrate a process for implanting a follicular unit, in accordance with some embodiments.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIGS. 1 and 2 depict an image-guided robotics system 25, including a robotic arm 27 with a tool assembly 30 attached to a distal tool plate 20. The tool assembly 30 includes coaxially disposed harvesting and implanting cannulas 38 and 36, respectively, extending from a tubular extension 24 of a housing 22. The cannulas 36 and 38 are axially stiff, e.g., made of a hard metal or plastic, and thin-walled to facilitate tissue penetration. The implanting cannula 36 has a needle-like tissue piecing tip, and the harvesting cannula has a tissue-coring (e.g., serrated) tip.

As described in detail the above-incorporated provisional application No. 60/764,173, the robotic arm 27 automatically and precisely positions the respective harvesting and implanting cannulas 38 and 36 at desired locations, and in desired orientations, along a body surface (e.g., a scalp) of a patient based on control signals derived at least in part from image data acquired by one or more cameras 28 attached to the tool assembly housing 22. Such automatic and precise positioning of the respective harvesting and implanting cannulas 38 and 36 is provided with a high degree of repeatability and accuracy (e.g. to 20 microns) by respective motors and encoders located in respective arm joints 21 of the robotic arm 27. Hair transplantation generally includes three steps: follicular unit harvesting, recipient site incision, and follicular unit placement in the incision. FIG. 3 shows one embodiment of a three-part tool 32 used for performing all three of these functions. Although the ensuing description of the three-part tool 32 is with reference to its use as part of the tool assembly 30 carried on the robotic arm 27 in the system 25 of FIG. 1, it will be appreciated that hand-held and operated embodiments of the three-pad tool 32 are also possible.

More particularly, the three-part tool 32 includes an outer (“implanting”) cannula 36 having an open, tissue-piercing (e.g., beveled) distal end 37 used for making incisions at recipient (implantation) sites in a body surface. An inner (“harvesting”) cannula 38 is coaxially positioned in an interior lumen of the implanting cannula 36, and has an open, tissue-coring (e.g., rough or serrated) distal end 40. The harvesting cannula 38 has an interior lumen appropriately sized for harvesting singular human hair follicular units by coring the respective follicular units and extracting them from a body surface (typically but not necessarily a scalp). By way of non-limiting examples, embodiments of the harvesting cannula 38 may have interior lumens that range from approximately 0.3 millimeters to 2.0 millimeters in diameter. In one embodiment, the harvesting cannula lumen has a diameter that is approximately 1 millimeter in diameter. Notably, different sized harvesting cannulas 38 may be used for harvesting single-follicle follicular units than for harvesting multi-follicle follicular units. In either case, an inner wall surface of the harvesting cannula lumen may be textured to facilitate frictional grasping the respective follicular units for extraction from the body surface after they are cored.

With reference also to FIGS. 4 and 5, the tool assembly 30 includes a motor drive assembly 60 mounted in the housing 22 and configured to receive and operatively engage the component parts of the three-part tool 32. In particular, the implanting cannula 36 is fixedly attached to a proximal hub 34, including a distal facing tapered portion 34 a and a proximally directed engagement portion 34 b. The engagement portion 34 b may be detachably-coupled (snap-fit) with a resilient gripper 63 extending from a tubular sleeve 65 in the motor drive assembly 60. In the illustrated embodiment, the gripper 63 comprises a plurality of resilient arm members 67 that are attached to or integral with, the tubular sleeve 65. It will be appreciated that other detachable coupling mechanisms may be employed in alternate embodiments. The tubular sleeve 65 engages a rack-and-pinion drive mechanism 81 driven by a first motor 62 of the motor drive assembly 60, so that, when the hub 34 is coupled to the gripper 63, the motor 62/drive mechanism 81 provide axial (i.e., reciprocating) motion of the implanting cannula 36 relative to the harvesting cannula 38 (and also relative to the tool assembly housing 22/24).

The harvesting cannula 38 extends proximally through a bore 45 of the implanting cannula hub 34 and implanting cannula 36, and is fixedly attached to distal chuck portion 43 a of a pin vise 43 seated in, and rotatable relative to, a bore of hub 34. An elongate body 46 is seated in, and fixedly attached to, the pin vise 43, and includes one or more radially-outward extending flanges 48 that engage a corresponding set of slots (not shown) in a distally projecting tubular drive member (not shown—extends internally through housing 93) coupled to an output gear 87 driven by a second motor 64 of the motor drive assembly 60 for thereby rotating the respective elongate body 65 and harvesting cannula 38, respectively, about a longitudinal axis of the harvesting cannula 38. As will be appreciated, a belt drive or other means for rotating the tubular drive member (and, thereby, the harvesting cannula 38) may be used in alternative embodiments. The elongate body 46 further includes a recessed section 44 located proximally of the flanges 48, which seats an annular retaining member 50 for detachably-coupling (via a snap-fit type connection) with the tubular drive member (proximal of the slots that engage flanges 48), thereby retaining the harvesting cannula 38 in position when the tool 32 is coupled with the motor dive assembly 60.

An elongate obturator 52 is slidably positioned in an interior lumen of the harvesting cannula 38, and has a proximal end attached to a seating member 54 that engages with a linear (“screw-drive”) drive mechanism (not shown) driven by a third motor 66 of the motor drive assembly 60 for selectively providing a distally-directed, “pushing” force on the obturator 52 relative to the harvesting cannula 38. A spring 53 is seated in an annular recess 49 formed in a proximal end-cap 51 of the elongate body 46, and extends (over the obturator 52) to the distal side of the seating member 54. The spring 53 applies a proximally-directed, “pulling” force on the seating member, to thereby bias the obturator against the screw drive.

The drive motor assembly further includes a “release” motor 67, that applies a distally-directed (pushing) force against the end-cap 51 via a tubular release member 86, which causes the respective attachment couplings (i.e., the implanting cannula hub 34 b and gripper 63, and the harvesting cannula retaining member 50 and the tubular drive member) to decouple for removal of the tool 32 from the tool assembly 30, e.g., for replacing one or both of the implanting and harvesting cannulas 36 and 38. In this manner, the multi-part tool 32 may be loaded into the tool assembly 30 by insertion (in the proximal direction) of the tool 32 (“back loaded”) through the tubular extension 24 of the housing 22, until the respective couplings 34 b and 50 snap into place with their counterparts in the motor drive assembly 60, and released by application of a sufficient force by the motor 67 on the release member 86 to decouple the respective couplings. A stop member 55 is attached to the obturator 52 that abuts the distal side of the end-cap as the release member 86 applies a downward force on the end-cap 51, so that the obturator 52 accompanies the rest of the tool 32 as it is released from the motor drive assembly 60 (and from the tool assembly 30).

The motor drive assembly 60 further comprises control circuitry for controlling operation of the respective motors 62, 64, 66, and 67. The control circuitry may include an independent processor (not shown) associated with the motor drive assembly 60, which receives as inputs information from the robotic system 25, including but not limited to positioning data obtained from images acquired of the respective cannulas 36, 38 and body surface/objects (e.g., hair follicles). Additionally or alternatively, a respective encoder may be operatively coupled with one or more of the motors 62, 64, 66, and 67 for tracking the relative movement and, thus, position information, of the implanting cannula 36, harvesting cannula 38, and/or obturator 52.

For harvesting a follicular unit from a body surface (e.g., a scalp), the robotic arm 27 positions and aligns the harvesting cannula 38 with a longitudinal axis of a selected follicular unit to be harvested. The harvesting cannula 38 is then advanced over the selected follicular unit by motion of the robotic arm 27, accompanied by simultaneous rotational movement of the harvesting cannula 38 about its longitudinal axis by the motor 64, with the open distal end 40 of the cannula 38 penetrating the body surface into the subcutaneous fatty layer surrounding and underlying the follicular unit. In alternate embodiments, a linear drive mechanism may be additionally provided in the motor drive assembly 60 for providing independently controlled axial translation of the harvesting cannula 38 relative to the tool assembly housing 20 (and implanting cannula 36). The harvesting cannula 38 is then withdrawn from the body surface by motion of the robotic arm 27 to thereby extract the follicular unit, which is carried in the lumen of the harvesting cannula. In some embodiments, a vacuum source may be selectively placed in communication with the harvesting cannula lumen to apply a proximally-directed “pulling” force to facilitate grasping and extracting the follicular unit, as well as to help retain the follicular unit in the harvesting cannula lumen after it has been harvested.

For implantation, the tool assembly 30 is repositioned by the robotic arm 27 to a selected implantation site on the body surface. At the implantation site, a longitudinal axis of the implanting cannula 36 is preferably aligned with a desired orientation of the follicular unit, when implanted. With reference to FIGS. 6A-B, the tissue-piercing distal end 37 of the implanting cannula 36 is advanced over the harvesting cannula 38 and into the body surface 68, creating a subcutaneous implantation cavity 70 of an appropriate depth and size for receiving the harvested follicular unit 72. This puncture motion by the cannula 36 is automatically controlled by motor 62, and is preferably very rapid in order to minimize trauma to the tissue surface 74 of the implantation cavity 70.

In one embodiment (shown in FIG. 6A), the follicular unit 72 is moved axially by the obturator 52 (under the control of motor 66) from the harvesting cannula lumen 76, where it has remained undisturbed since it was harvested, into a distal end portion of the implanting cannula lumen 78. This repositioning of the follicular unit 72 from the harvesting cannula lumen 76 into the implanting cannula lumen 78 may take place before, during, or after the implanting cannula 36 has punctured the body surface 68. The obturator thereafter maintains the follicular unit 72 in the implantation cavity 70 as the implanting cannula 36 is withdrawn from the body surface 68 by translational movement relative to the obturator 52. Once the implanting cannula 36 is withdrawn, the obturator 52 is also withdrawn, with the follicular unit 72 implanted in the body surface. A distal facing end 80 of the obturator 52 is preferably recessed to allow room for one or more hair follicles 82 protruding from the follicular unit 72.

In another embodiment (shown in FIG. 6B), the respective distal ends of the implanting and harvesting cannulas 36 and 38 are aligned (i.e., by relative movement of the implanting cannula 36) so that their respective distal ends 37 and 40 are approximately coextensive. This alignment of the respective cannula distal ends 37 and 40 may take place before, during, or after the implanting cannula penetrates the body surface to form the implantation cavity 70. Thereafter, the respective cannulas 36 and 38 are withdrawn from the implantation cavity 70, while the follicular unit 72 is retained therein, i.e., by simultaneous movement of the robotic arm 27 away from the body surface 68 and of the obturator 52 towards the body surface 68. In alternate embodiments having a linear drive mechanism in the motor drive assembly 60 for providing independently controlled axial translation of the harvesting cannula 38 relative to the tool assembly housing 20 (and implanting cannula 36), the respective cannulas 36 and 38 may be withdrawn from the implantation cavity 70 relative to (and without requiring simultaneous movement of) the obturator 52 by operation of the motor drive assembly 60. In other alternate embodiments, a source of pressurized air selectively placed in communication with the harvesting cannula lumen 76 may be used to retain the follicular unit 72 in the implantation cavity 70 as the cannulas 36 and 38 are withdrawn.

FIG. 7 illustrates a distal portion of the robotics system 25 in accordance with some embodiments of the invention. A force sensor 100 is secured to an arm 104, a plate 102 mounted to the force sensor 100, and a motor drive, or “positioning” assembly 106 secured to the plate 102. Alternatively, the plate 102 could be secured directly to the arm 104, in which cases, the force sensor 100 may be secured between the positioning assembly 106 and the plate 102. Alternatively, the force sensor 100 may be located within the positioning assembly 106. The force sensor 100 is configured to sense three forces Fx, Fy, Fz in three different orthogonal directions X, Y, Z, and three orthogonal moments Mx, My, Mz. In other embodiments, the force sensor 100 may be configured to sense one or two of the forces Fx, Fy, Fz, and/or one or two of the moments Mx, My, Mz. As shown in the figure, the force sensor 100 is coupled to a computer 120, which receives data from the force sensor 100 representing the sensed force(s) and/or moment(s). In other embodiments, the force sensor data may go directly to the robot.

During the above harvesting and implanting process, the force sensor 100 monitors one or more force/moment component transmitted from the positioning assembly 106. For example, the force sensor 100 may monitor a force Fz, which has a directional vector that is approximately parallel to an axis of a harvesting cannula 200. The sensed force Fz is transmitted to the computer 120, which determines whether a magnitude of the sensed force Fz is within an acceptable limit. In some embodiments, the computer 120 is configured (e.g., programmed) to stop a harvest process or an implant process if the sensed force Fz exceeds a prescribed limit, which may indicate that the harvesting cannula 200 or the implanting cannula 202 is pressing against the skull, for example. As such, the force sensor 100 provides a safety feature that prevents the harvesting cannula 200 and the implanting cannula 202 from injuring a patient in an unintended way.

In the illustrated embodiments, the positioning assembly 106 includes a holding unit 109 for engagement with a cannula assembly 110, and a plurality of positioners 107 a-10 c. The holding unit 109 is configured to engage with different parts of the cannula assembly 110 so that the cannula assembly 110, as a whole, can be positioned by the positioning assembly 106. The holding unit 109 also allows different components of the cannula assembly 110 to be controlled after the cannula assembly 110 is engaged with the holding unit 109. The positioners 107 a-107 c are configured for moving different components of the cannula assembly 110 after it has been engaged with the holding unit. Although three positioners 107 a-107 c are shown, in other embodiments, the positioning assembly 106 may include more or less than three positioners 107. In some embodiments, the positioning assembly 106 may include the motor drive assembly of FIG. 5, which includes three motors (positioners) for moving different components of the cannula assembly 110, plus an additional motor for disengaging the cannula assembly 110 from the positioning assembly.

FIG. 8 illustrates the holding unit 109 in accordance with some embodiments. The holding unit 109 includes a first engagement portion 122 for engaging a first portion of the cannula assembly 110, a second engagement portion 124 for engaging a second portion of the cannula assembly 110, and a third engagement portion 126 for engaging a third portion of the cannula assembly 110.

FIG. 9A illustrates the cannula assembly 110 in accordance with some embodiments. The cannula assembly 110 has a similar configuration as the tool 32 shown in FIGS. 3-4. The cannula assembly 110 includes a harvesting cannula 200, an implanting cannula 202, and a plunger (obturator) 204. The harvesting cannula 200 has a proximal end 212, a distal end 214, a body 215 extending between the proximal and distal ends 212, 214, and a lumen 217 defined at least partially by the body 215. In the illustrated embodiments, the lumen 217 has a cross sectional dimension that is between 0.3 millimeter and 2.0 millimeters, and more preferably, approximately 1 millimeter. The cannula assembly 110 further includes a shaft 216 having a proximal end 218, a distal end 220, and a lumen 222 extending between the proximal and distal ends 218, 220. The proximal end 212 of the harvesting cannula 200 is secured to the distal end 220 of the shaft 216. The implanting cannula 202 has a proximal end 232, a distal end 234, a body 230 extending between the proximal and distal ends 232, 234, and a lumen 236 within the body 230. The lumen 236 has a cross sectional dimension sized for accommodating at least a portion of the harvesting cannula 200, and for allowing the harvesting cannula 200 to slide relative to the implanting cannula 202. The distal end 234 of the implanting cannula 202 has a sharp tip 250 for piercing tissue.

In the illustrated embodiments, the distal end 214 of the harvesting cannula 200 has a tubular configuration (FIG. 9B). In such cases, the edge 252 of the harvesting cannula 200 may have a sharp configuration for allowing the harvesting cannula 200 to penetrate tissue. In other embodiments, the distal end 214 of the harvesting cannula 200 may have an arc configuration (FIG. 9C). In such cases, the ends 254 of the arc portion may have a sharp configuration for allowing the harvesting cannula 200 to cut tissue as the harvesting cannula 200 is rotated about its axis. In further embodiments, the distal end 214 of the harvesting cannula 200 can include a plurality of cutting portions 256, with each cutting portion 256 having a sharp edge 258 for cutting tissue (FIG. 9D). It should be noted that the distal end 214 of the harvesting cannula 200 is not limited to the examples described previously, and that the distal end 214 can have other configurations in other embodiments, as long as it can core tissue.

The cannula assembly 110 further includes a first engagement portion 238 and a second engagement portion 240. The first engagement portion 238 has a tubular configuration, and is secured to the shaft 216. The second engagement portion also has a tubular configuration, and is secured to the proximal end 232 of the implanting cannula 202. proximal end 232 of the implanting cannula 202. The first and the second engagement portions 238, 240 are sized and shaped to engage with corresponding components of the holding unit 109. It should be noted that the first and second engagement portions 238, 240 are not limited to the example of the configuration illustrated, and that the engagement portions 238, 240 can have other configurations in other embodiments. For example, in alternative embodiments, the engagement portion 238 does not have a tubular configuration. In such cases, the engagement portion 238 can be a structure that is secured to, or extends from, a surface of the shaft 216. Similarly, in other embodiments, the engagement portion 240 can be a structure that is secured to, or extends from, a surface of the implanting cannula 202, and needs not have a tubular configuration. As shown in the figure, the cannula assembly 110 also includes a connector 248 secured to the shaft 216. The connector 248 has a shape that resembles a sphere, but may have other shapes in other embodiments.

The plunger 204 has a proximal end 242 and a distal end 244. The plunger 204 is at least partially located within the lumen 217 of the harvesting cannula 200, and is slidable relative to the harvesting cannula 200. The cannula assembly 110 further includes a spring 246 coupled to the plunger 204 for biasing the plunger 204 in a proximal direction relative to the harvesting cannula 200. In the illustrated embodiments, the plunger 204 is described as a component of the cannula assembly 110. In other embodiments, the plunger 204 is not a part of the cannula assembly 110. For example, the plunger 204 may be a component of the positioning assembly 106.

FIG. 10 illustrates the cannula assembly 110 that has been engaged with the positioning assembly 106. When the cannula assembly 110 is snapped onto the positioning assembly 106, the first engagement portion 122 of the holding unit 109 is engaged with the connector 248, the second engagement portion 124 is engaged with the first engagement portion 238 of the cannula assembly 110, and the third engagement portion 126 is engaged with the second engagement portion 240 of the cannula assembly. The connector 248 allows the cannula assembly 110 to be detachably secured to the positioning assembly 106. The first engagement portion 122 of the holding unit 109 is coupled to the first positioner 107 a. In some embodiments, the harvesting cannula 200 is not translatable. In alternative embodiments, the first positioner 107 a is configured to translate (e.g., advance or retract) the harvesting cannula 200. The second engagement portion 124 of the holding unit 109 is coupled to the second positioner 107 b, which is configured to rotate the harvesting cannula 200 about its axis. The third engagement portion 126 of the holding unit 109 is coupled to the third positioner 107 c, which is configured to translate (e.g., advance or retract) the implanting cannula 202.

In other embodiments, the second engagement portion 124 of the holding unit 109 may be coupled to both the first positioner 107 a and the second positioner 107 b. In such cases, the first positioner 107 a is configured to translate the engagement portion 124 to thereby advance or retract the harvesting cannula 200, and the second positioner 107 b is configured to rotate the engagement portion 124 to thereby turn the harvesting cannula 200 about its axis. In further embodiments, the second positioner 107 b is not needed, and the cannula assembly 110 does not include the engagement portion 238. In such cases, the positioning assembly 106 is not configured to rotate the harvesting cannula 200, but to advance and retract the harvesting cannula 200 in a back and forth trusting motion. In still further embodiments, the third positioner 107 c is not needed, and the third engagement portion 126 is fixedly secured to the holding unit 109. In such cases, the implanting cannula 202 may be positioned by the robotic arm 27, and the harvesting cannula 200 may be positioned relative to the implanting cannula 202 using the first positioner 107 a.

When using the cannula assembly 110 to harvest a follicular unit, the cannula assembly 110 is first coupled to the positioning assembly 106. Such may be accomplished manually by snapping the cannula assembly 110 onto the positioning assembly 106. Alternatively, the cannula assembly 110 may be held upright by a stand (not shown). In such cases, the robotic arm 27 may be used to move the positioning assembly 106 to “grab” the cannula assembly 110 from the stand. The camera(s) 28 may be used to provide information regarding a position of the cannula assembly 110 to the processor 120, which controls the robotic arm 27 based on the information, thereby placing the positioning assembly 106 in engagement position relative to the cannula assembly 110.

Next, a treatment plan is input into the computer 120. In some embodiments, the treatment plan is a prescribed plan designed to transplant hair follicular units from a first region (harvest region) to a target region (implant region). In such cases, the treatment plan may include one or more parameters, such as a number of hair follicular units to be removed/implanted, location of harvest region, location of implant region, a degree of randomness associated with targeted implant locations, spacing between adjacent targeted implant locations, depth of follicle, depth of implant, patient identification, geometric profile of harvest region, geometric profile of implant region, marker location(s), and density of targeted implant locations. Various techniques may be used to input the treatment plan into the computer 120. In the illustrated embodiments, the treatment plan may be input using a user interface that includes a monitor 122 and a keyboard 124. Alternatively, the treatment plan may be input using a storage device, such as a diskette or a compact disk. In other embodiments, the treatment plan may be downloaded from a remote server. In further embodiments, the treatment plan may be input using a combination of the above techniques. For example, some parameters may be input into the computer 120 using a diskette, while other parameters may be input using the user interface. In some embodiments, one or more parameters of the treatment plan may be determined in real time (e.g., during a treatment session).

After the treatment plan has been input into the computer 120, the computer 120 then registers the treatment plan with a patient. In some embodiments, such may be accomplished by using the camera(s) 28 to identify one or more markers on the patient. The marker may be a reflector that is secured to the patient, an ink mark drawn on the patient, or an anatomy of the patient. The identified marker(s) may be used to determine a position and/or orientation of a target region on the patient. In the illustrated embodiments, the treatment plan includes a position of the harvest (or donor) region. Using input from the camera(s) 28, the computer 120 identifies the location of the harvest region on the patient, and a target follicular unit in the harvest region. The computer 120 then operates the robotic arm 27 to place the distal end 214 of the harvesting cannula 200 next to the target follicular unit. In some embodiments, the harvesting cannula 200 is positioned coaxially with the target follicular unit.

Next, the harvesting cannula 200 is used to harvest the target follicular unit. In some embodiments, such may be accomplished by activating a positioner within the positioning assembly 106 to rotate the harvesting cannula 200. As the harvesting cannula 200 is rotated, the harvesting cannula 200 may be advanced distally (e.g., by activating another positioner within the positioning assembly 106, or by moving the positioning assembly 106 using the robotic arm 27). In other embodiments, the harvesting of the target follicle 302 unit may be accomplished by thrusting the harvesting cannula 200 forward and backward. While the harvesting cannula 200 is used to core out the follicular unit 302, the implanting cannula 202 is located proximally away from the distal end 214 of the harvesting cannula 200 to thereby prevent interference with the harvesting procedure. Such may be accomplished by advancing the harvesting cannula 200 distally relative to the implanting cannula 202, or alternatively, by retracting the implanting cannula 202 proximally relative to the harvesting cannula 200 (if the implanting cannula 202 can be positioned).

When the distal end 214 of the harvesting cannula 200 has been advanced within a prescribed depth, e.g., 5 millimeter, below the skin surface, the harvesting cannula 200 is then retracted and removed from the patient. The camera(s) 28 may be used to monitor the harvesting process to thereby determine how far the harvesting cannula 200 has been advanced below the skin surface 306. In some embodiments, the exterior of the harvesting cannula 200 may include marker lines to thereby allow the camera(s) 28 or a physician to “see” how much of the harvesting cannula 200 has been advanced into the patient. In some embodiments, surface friction at the interface between the follicular unit 302 and the interior surface 304 within the lumen 217 will hold the follicular unit 302 as the harvesting cannula 200 is removed from the patient, thereby harvesting the follicular unit 302. In other embodiments, the interior surface 304 can be texturized (e.g., having one or more indents or protrusions) to thereby allow the distal end 214 to more easily hold onto the follicular unit 302 as the harvesting cannula 200 is removed from the patient. In further embodiments, a proximal end of the cannula assembly 110 may be coupled to a vacuum unit (not shown) located within the positioning assembly 106. In such cases, the vacuum unit creates suction within the lumen 217 of the harvesting cannula 200, to thereby pull the target follicular unit 302 away from its underlying tissue as the harvesting cannula 200 is removed from the patient.

After the follicular unit 302 has been harvested, the positioning assembly 106 retracts the harvesting cannula 200 proximally until the distal end 214 is proximal to the distal end 234 of the implanting cannula 202. Alternatively, if the implanting cannula 202 is positionable, the implanting cannula 202 may be advanced distally until the distal end 234 is distal to the distal end 214 of the harvesting cannula 200. Next, the computer 120 operates the robotic arm 27 to place the distal end 234 of the implanting cannula 202 adjacent to a target location within an implant region of the patient as prescribed by the treatment plan. The implanting cannula 202 is then advanced (e.g., by activating a positioner within the positioning assembly 106, or by moving the positioning assembly 106 distally towards the target location) to pierce through the skin 310 at the implant region (FIG. 11A). The implanting cannula 202 is advanced until the penetrated depth 312 is at least equal to the coring depth 300. In some embodiments, the camera(s) 28 and the computer 120 may be used to determine an amount of the implanting cannula 202 that has been advanced into the patient. For example, the implanting cannula 202 may include a plurality of marker lines for allowing the camera(s) 28 or a physician to “see” how much of the implanting cannula 202 has been inserted into the patient. As shown in the figure, the implanting cannula 202 creates an opening 314 below the patient's skin 314, in which the follicular unit 302 may be placed.

Next, the harvesting cannula 200, which contains the harvested follicular unit 302, is advanced within the lumen 236 of the implanting cannula 202, until a top surface 320 of the follicular unit 302 is at or below the skin 310 at the implant region (FIG. 11B). Next, the plunger 204 may be advanced distally (e.g., by using another positioner within the positioning assembly 106) until its distal end 244 engages with the follicular unit 302 located within the harvesting cannula 200 (FIG. 11C). The implanting cannula 202 and the harvesting cannula 200 are then retracted proximally relative to the plunger 204, thereby leaving the follicular unit 302 implanted at the target location in the implant region (FIG. 11D). In other embodiments, the cannula assembly 110 does not include the plunger 204. In such cases, a pressure generator (not shown) located within the positioning assembly 106 may be used to create a pressure within the lumen 217 of the harvesting cannula 200, thereby pushing the follicular unit 302 towards the patient as the implanting cannula 202 and the harvesting cannula 200 is retracted. Such technique will cause the follicular unit 302 to dislodge from the harvesting cannula 200 while the harvesting cannula 200 is being removed from the patient.

After the first follicular unit 302 has been implanted in the implant region, the harvesting cannula 200 is advanced distally until its distal end 214 is distal to the distal end 234 of the implanting cannula 202. The computer 120 then operates the robotic arm 27 again to place the harvesting cannula 200 next to another target follicular unit 302 to be harvested. The above described process is then repeated to harvest the next follicular unit 302, and to implant the follicular unit 302. The selection of the follicular unit 302 may be determined by the computer 120. For example, in some embodiments, based on a location and geometry of the prescribed harvest region, the computer 120 selects a follicular unit 302 only if it is within the prescribed harvest region. In some embodiments, the above process is repeated until a prescribed number of follicular units 302 have been implanted in the implant region, until a density of the implanted follicle units 302 reaches a prescribed density, or until there is no more available follicular unit 302 in the harvest region.

In some embodiments of the invention employing an automated positioning system, an attending physician or operator may still specify where a follicular unit needs to be implanted and at what angle, i.e., its relative location (or “implantation site”), orientation, and depth. For example, specification of a location, orientation, and/or depth of a follicular unit to be implanted may be carried out by a treatment planning system. Alternatively, during the implanting mode, when the camera(s) are viewing the recipient area of the scalp, the attending operator may use a user interface (e.g., a conventional computer mouse) to specify the implant location and/or position and/or orientation and/or implant depth. Alternatively, the operator can point to location on the scalp by placing a temporary fiducial, such as an ink mark or a pointer that can be visualized, identified, and measured by the image processing system. Further, orientation can be specified directly on the computer monitor as a combination of two angles, such as rotation about x-axis and a rotation about y-axis (assuming that z-axis is along the cannula), or by placing an elongated pointer on the scalp, which the image processing system can visualize and measure the angles.

In any case, the control of the robotic arm now becomes two steps. First, based on the specification of the location and orientation of the implant location, the computer processor directs the robotic arm to move the implanting cannula to a desired location and orientation. Second, the actual advancement of the implanting cannula into the skin surface takes place, either solely by actuating the mechanism, or by a combination of robotic arm movement and mechanism actuation, in which the desired implant depth is achieved. Another way of specifying the orientation of the implanted follicular unit is to have the system match to the orientation of the one or more hair follicles extending there from to the orientation of existing hair follicles in the area of implantation. The system, after positioning the implanting cannula at the implantation location, visualizes and measures the orientation of neighboring hair follicles, and uses this information to determine an appropriate orientation of the follicular unit being implanted. In the case of neighboring hair follicles having different orientations, the system may, for example, obtain a weighted average of the various orientations for determining an orientation of the follicular unit being implanted.

The forgoing illustrated and described embodiments of the invention are susceptible to various modifications and alternative forms, and it should be understood that the invention generally, as well as the specific embodiments described herein, are not limited to the particular forms or methods disclosed, but also cover all modifications, equivalents and alternatives falling within the scope of the appended claims. By way of non-limiting example, it will be appreciated by those skilled in the art that the invention is not limited to the use of a robotic system, and that other automated, semi-automated, and manual systems and apparatus may be used for positioning and actuating the respective components of the multi-part tool assembly adjacent the body surface. 

1. A method of transplanting a hair follicular unit using a multi-part tool assembly, the tool assembly comprising coaxially disposed harvesting and implanting cannulas, the method comprising: positioning the harvesting cannula in proximity of a selected follicular unit to be harvested from a donor area of a body surface; advancing the harvesting cannula relative to the donor area of the body surface so that an open, tissue coring distal end of the harvesting cannula penetrates the body surface surrounding the selected follicular unit to a depth sufficient to substantially encapsulate the follicular unit; withdrawing the harvesting cannula from the body surface with the follicular unit engaged by and retained in an interior lumen of the harvesting cannula; advancing a tissue piercing end of the implanting cannula over the harvesting cannula to puncture a recipient area in the body surface and to form an implantation cavity therein; and displacing the follicular unit from the harvesting cannula lumen into the implantation cavity.
 2. The method of claim 1, wherein the tool assembly is attached to a moveable arm of an automated system.
 3. The method of claim 2, wherein the automated system is a robotic system, and the moveable arm is a robotic arm.
 4. The method of claim 1, wherein advancing the distal end of the harvesting cannula into the body surface comprises rotating harvesting cannula about its longitudinal axis.
 5. The method of claim 1, wherein the follicular unit is displaced from the harvesting cannula lumen by an obturator positioned in the harvesting cannula lumen.
 6. The method of claim 1, wherein the follicular unit is displaced from the harvesting cannula lumen by pressurized air.
 7. The method of claim 1, wherein at least one of the harvesting and implanting cannulas is advanced into the body surface by actuating one or more motors of a motor drive assembly operatively coupled to the tool assembly to thereby cause translational movement of the respective harvesting or implanting cannula relative to the other.
 8. The method of claim 7, wherein the motor drive assembly is processor-controlled.
 9. The method of claim 8, wherein the processor determines relative positions of the harvesting and implanting cannulas based at least in part on image data received from one or more cameras.
 10. The method of claim 8, wherein the processor determines relative positions of the harvesting and implanting cannulas based at least in pail on positional data received from one or more encoders operatively associated with the motor drive assembly.
 11. The method of claim 1, wherein displacing the follicular unit from the harvesting cannula lumen into the implantation cavity comprises advancing an obturator positioned in the harvesting cannula lumen relative to the harvesting cannula so as to displace the follicular unit from the harvesting cannula lumen into the implantation cavity within the lumen of the implanting cannula, and withdrawing the distal end of the implanting cannula from the implantation cavity while the obturator retains the follicular unit therein.
 12. The method of claim 1, wherein displacing the follicular unit from the harvesting cannula lumen into the implantation cavity comprises advancing the harvesting cannula relative to the implanting cannula so that their respective distal ends are approximately coextensive in the implantation cavity, and retaining the follicular unit in the implantation cavity, while withdrawing each of the harvesting and implanting cannulas from the implantation cavity.
 13. The method of claim 12, wherein the follicular unit is retained in the implantation cavity by an obturator positioned in the harvesting cannula lumen.
 14. The method of claim 1, wherein advancing the harvesting cannula relative to the body surface is performed by one or more of (1) movement of the harvesting cannula relative to the tool assembly, (2) movement of an operator's arm, (3) movement of an automated arm to which the harvesting cannula may be attached, or (4) movement of the harvesting cannula relative to the automated arm to which the harvesting cannula may be attached.
 15. The method of claim 1, further comprising placing the harvesting cannula lumen in communication with a source of negative pressure to help extract retain the follicular unit therein.
 16. The method of claim 1, wherein the tool assembly further comprises a force sensor, and wherein the method further comprises stopping operation of one or both of the harvesting and implanting cannulas if a force sensed by the force sensor exceeds a prescribed limit.
 17. A method of transplanting a hair follicular unit using a multi-part tool assembly carried on a moveable arm of an automated system, the tool assembly comprising coaxially disposed harvesting and implanting cannulas, the method comprising: positioning the moveable arm so as to place the harvesting cannula in proximity with a selected follicular unit to be harvested from a donor area; advancing the harvesting cannula relative to the donor area so that an open, tissue coring distal end of the harvesting cannula penetrates a surface surrounding the selected follicular unit to a depth sufficient to substantially encapsulate the follicular unit, and when harvesting, a tissue-piercing distal end of the implanting cannula is located proximal to the distal end of the harvesting cannula; withdrawing the harvesting cannula from the donor area with the follicular unit engaged by and retained in an interior lumen of the harvesting cannula; positioning the moveable arm so that the tissue-piercing distal end of the implanting cannula is located adjacent a recipient area in a body surface; advancing the tissue piercing distal end of the implanting cannula to puncture the recipient area of the body surface and form an implantation cavity therein; and displacing the follicular unit from the harvesting cannula lumen into the implantation cavity.
 18. The method of claim 17, wherein placing the harvesting cannula in proximity with the selected follicular unit comprises aligning a longitudinal axis of the harvesting cannula with a longitudinal axis of the selected follicular unit.
 19. The method of claim 17, wherein the automated system is a robotic system, and the moveable arm is a robotic arm.
 20. The method of claim 17, wherein at least one of the harvesting and implanting cannulas is advanced by actuating one or more motors configured to move the at least one of the harvesting and implanting cannulas relative to the moveable arm, the one or more motors further configured to cause translational movement of the respective harvesting or implanting cannula relative to the other.
 21. The method of claim 20, wherein operation of one or more motors is processor-controlled.
 22. The method of claim 17, further comprising tracking a relative movement of the implanting and harvesting cannulas.
 23. The method of claim 17, wherein advancing the distal end of the harvesting cannula relative to the donor area comprises rotating the harvesting cannula about its longitudinal axis.
 24. The method of claim 17, wherein the follicular unit is displaced from the harvesting cannula lumen by an obturator positioned in the harvesting cannula lumen.
 25. The method of claim 17, wherein the follicular unit is displaced from the harvesting cannula lumen by pressurized air.
 26. The method of claim 17, wherein displacing the follicular unit from the harvesting caimula lumen into the implantation cavity takes place before, during, or after the implanting cannula punctures the recipient area surface.
 27. The method of claim 17, wherein the automated system further comprises a force sensor, and wherein the method further comprises stopping operation of one or both of the harvesting and implanting cannulas if a force sensed from the force sensor exceeds a prescribed limit.
 28. The method of claim 27, wherein stopping operation of one or both of the harvesting and implanting cannulas is controlled by control circuitry.
 29. A method of transplanting a hair follicular unit using a tool assembly comprising coaxially disposed harvesting and implanting cannulas and an automated positioning system operatively coupled to the cannulas, the method comprising: aligning the harvesting cannula of the tool assembly with a selected follicular unit to be harvested from a donor area of a body surface; advancing the harvesting cannula relative to the donor area so that an open, tissue coring distal end of the harvesting cannula penetrates the surface surrounding the selected follicular unit to a depth sufficient to substantially encapsulate the follicular unit, and when harvesting, a tissue-piercing distal end of the implanting cannula is located proximal to the distal end of the harvesting cannula; withdrawing the harvesting cannula distal end from the donor area with the follicular unit engaged by and retained in an interior lumen of the harvesting cannula; advancing the implanting cannula of the tool assembly relative to a recipient area of the body surface so that the tissue piercing distal end of the implanting cannula punctures the body surface and forms an implantation cavity therein; and displacing the follicular unit from the harvesting cannula lumen into the implantation cavity using an obturator slidably positioned in the harvesting cannula lumen, wherein at least one of the harvesting and implanting cannula is advanced by actuating one or more motors of the automated positioning system to cause translational movement of the respective harvesting or implanting cannula relative to the other. 